We have used these and they are great. Ours are a few years old, Motorola Talkabouts, but we're taking them with us in June. We sometimes had to change channels because someone else is on the same one, but we used them traveling in the car too. Some of the rides block the signal, I think we had problems in Splash Mountain & Space Mountain, but other than that we really didn't have much of a problem. I would guess they have even better ones out now, so go for it.
Robin